In this project, mechanisms of normal cellular immunity and tumor immunology are studied: immunological surveillance of cancer patients and the effects of chemotherapy and immunotherapy on the immune response are explored. We are characterizing acute lymphocytic leukemia according to the immunological subtypes of lymphoblasts and the capacity of lymphoblasts to express immunoregulatory helper and/or suppressor functions in vitro. The role of B cell alloantigens in lymphoblastic leukemia is also under investigation. Particular emphasis is placed on immunologic study of the monocyte-macrophage system (including development of new clinical assays of human monocyte function) in malignancies and immunodeficiency diseases, in the newborn, and in malignant histiocytosis. We are also investigating serum suppressors of cellular immunity in cancer patients, and the role of immune adjuvants and their ability to stimulate granulocyte recovery following marrow-suppressive chemotherapy. BIBLIOGRAPHIC REFERENCES: Gerety, R., Poplack, D.G., Hoofnagle, J.H., Barker, L.F., and Blaese, R.M.: Hepatitis B virus infection in the Wiskott-Aldrich syndrome. J. Pediat. 88: 561-564, 1976. Korski, I.R., Poplack, D.G., and Blaese, R.M.: A nonspecific esterase stain for the identification of monocytes and macrophages. In Bloom, B.R. and David, J.R. (Eds.): In Vitro Methods in Cell-mediated and Tumor Immunity. New York, Academic Press, 1976, pp. 359-362.